Typewriting machine



Oct. 9 I

' A. G. F. KUROWSKI TYPEWRITING MACHINE Filed Sept. 5, 192'! Patented(let. 9 192 8.

UNITED STATES 1,687,026 PATENT OFFICE.

ALFRED G. F. KUROWSKI, BROOKLYN, NEW YORK, ASSIGNOB 'JJO UNDERWOOT)ELLIOTT FISHER COMPANY, NEW YORK, N. Y., A CORPORATION OF DELAWARE.

TYPEWRITING MACHINE.

Application filed September 3, 1927. Serial No. 217,322.

This invention relates generally to counterbalancing springs forplaten-shift typewriting machines, and more particularly to devices forfastening such springs in operative position on a typewriting machine.

In an Underwood typewriting machine, to reduce the effort for operatingthe usual shift-key, a counterbalancing tensile spring having both endsformed with a bend or hooked around a depending bracket fast on theframe of the machine and its rear end hooked on a dependingelementof abell crank, which is swung upwardly for shifting the platen-frame toupper-case position upon operation of the shift-key.

In most cases,the present arrangement of the above-mentionedcounterbalancing spring is entirely satisfactory. It has been found,

= however, that in some offices and in some business schools personsusing an Underwood typewriting machine occasionally will carelessly orfrom ulterior motives displace from operative posit-ion or even entirelyremove the usual counterbalancing spring.

It is an object of the present invention to provide devices for'securingthe platen-shift counterbalancing spring on an Underwood typewritingmachine so that it cannot be easily removed therefrom or madeinoperative. 1

In carrying out my invention, the counterbalancing spring has both endsarranged with integral closed rings, and a notched plate is fastened onthe usual depending notched bracket, to which is fastened the forwardend of the counterbalancing spring so that a virtual eye or hole isbuilt up forsecuring the front end of the spring in place. The rear endof the spring is adjustably fastened .to the usual notched bell-crank bymeans of a link having its rear end provided with a tooth for engagingthe teeth of the notched bell-crank member. The front end of the link isarranged with a collar held in place by an upset screw, around whichcollar the rear end of the spring engages.

. Other features and advantages will hereinafter appear.

In the acompanying drawings,

' Figure 1 is a fragmentary view of an Underwood typewriting machine,having my invention applied thereto. I

Figure 2 is a bottom view, broken away in part, of the counterbalancingspring and the hook is provided, and has its front end.

devicesof'the present invention for fastenlng it'to the typewritingmachine. I

Figure 3 is a disassembled perspective view, partly broken away, ofthe-counterbalancing spring of the present invention,

the usual bracket to which the front end of the spring is attached, andthe'devices of the present invention for securing the Spring tothebracket and to the bell-crank, the latter not being shOWn in this view.

In an Underwood typewriting machine,

types 10 strike against a platen 11 on a shaft 12 journaled in the sidesof a platen-frame 13, which may be swung for case-shift movement on acarriage 14 by ,instrumentalities including two arms 15, one at each endof the platen-frame. The rear ends of'the arms may be fast on arock-shaft16, and the front ends engage gudgeons 17. fixed on the sidesof the platen-frame The platen 11 may be raised to uppercase position byoperation of the usual shift-key, not shown, which swings bell-crank 20upwardly. Such a spring is shown in the patent to l/Villiam F. Helmond,

No. 1,066,275, dated Julyl, 1913. Its forward end is usually formed witha bend or hook which engages in a notch 27 of a depending bracket 29which is fastened by screws 30 to a convenient portion of a main frame31 of the typewriting machine. The rear end of the liftrail spring isusually formed substantially like the forward end for engaging in anydesired notch between a plurality of teeth 32 provided in a rear uprightportion of a usual connecting piece or bracket 33, extending betweentheouter ends of the arms 19 and 22.

While the construction of the lift-rail spring in the above-mentionedpatent to Helmond is generally quite satisfactory, it has been found incertain offices and in business schools that some persons, in using anUnderwood typewriter, will accidently or intentionally displace orremove the usual lift-rail spring connecting an arm 28 of the bracket 29and the bell-crank 20. To provide means for preventing the easy removalof the kind of lift-rail spring mentioned above, which can be easilyattached to a standard Underwood typewriting machine without alterationor change in the latter, a link or clevis 34 has two forwardly-extendingside members or arms 35 integrally joined by a rear end piece 36, thearms being spaced apart for engaging loosely around the sides of thebracket 33. A tooth 37, for engaging in the notches between the teeth32, may be formed by bending an integral lug on the end piece 36forwardly and downwardly. The forward end of each arm 35 may'have a hole38, the holes being oppositely positioned and one of them tapped forreceiving a screw 39, which passes through the other hole and through asmall spacing collar 40 to hold it in place between the arms 35. Thethickness of the collar slightly er;- ceeds the diameter of the coiledtensile spring 41 whose'rear end will terminate in a closed loop 42large enough in diameter to loosely engage around the collar 40. Theforward end of the spring 41 will terminate in a closed loop or ring 43which engages in the usual forwardly-opening notch 27 in the arm 28. Toprevent the removal of the loop 43 from the arm, a substantiallyT-shaped sheet-metal plate 44 is provided with a rearw ardly-openingnotch 45 in its upright member 44*, arranged for loosely fitting overthe portion of the loop 43 adjacent the notch 27 when the plate 44 isfastened on the arm 28 by means of a short mounting plate 46 havingtapped holes 47 to receive screws 48 passing on each side of thebracket-arm 28 in close proximity thereto through holes 49 in the endsof an upper lateral member 44 of the T shaped plate 44. Theoppositely-disposed notches 27 and 45 form, in effect, a built-up eye orhole for the loop 43, from i which it cannot be removed without firsttaking out the screws 48, whose removal may be prevented by upsettingthe leading ends of the screws 48 after they have passed through theplate 46 (Figure 2). It will be noted that the notch 27, the loop 43,and the notch 45 co operate to prevent the removal of the plate 44 byslipping it off the bracket 29. The sides of the notch 45, when moved,will be stopped by striking the wire rim of the loop 43 which is heldagainst displacement by engagement with the sides of the notch 27. Afterthe loop 42 has been placed around the collar 40, and the screw 39threaded through the tapped hole in the arm 35 (Figure 2), the leadingend of the screw may be upset to prevent its removal.

It will be noted that the arrangement of the arms 35 and tooth 37permits the link 34 to have a compact, positive, adjustable engagementwith the bell-crank 20, which is unreleasable by the typist without theuse of special tools, which, if employed, would attract immediateattention.

Variations may be resorted to within the scope of the invention, andportions of the improvements may be used without others. Having thusdescribed my invention, I claim:

1. In a platen-shift typewriting machine, the combination with anupwardly-shiftable bell-crank supporting the platen of said machine, anda bracket disposed forwardly. from said bell-crank and having a forwardly-opening notch, of a coiled wire counterbalancing spring for saidplaten, having each end terminating in a closed ring or loop, theforward loop engaging around said bracket to lie in said notch, a platedisposed against said bracket and having a rearwardly-opening notchregistering with said first-named notch, whereby to form a builtup eyewhose rim engages around the vwire rim of the forward ring of saidspring, instrumentalities for fastening said plate to said bracket, andan undetachable built-up link for fastening the rear end of said springto said bell-crank.

2. In a platen-shift typewriting machine, a built-up link forunreleasably fastening a counterbalancing spring having a closedring-like end-portion to a platen-shifting instiaunentality of saidmachine, having an upright row of angular notches, said link includingside'members integrally joined at the rear, one of said members having aplain hole at the front end and the other side member having anoppositely-disposed tapped hole, a screw passing through said plain holeand threaded in said tapped hole and passed th'erethrough and upset toprevent its withdrawal, a collar around said screw between said sidemembers, and a tooth bent forwardly and inclined downwardly between saidside members at the rear thereof for engaging in the notches in saidplatenshifting instrumentality,

3. In a platen-shift typewriting machine, in combination, 'a bell-crankfor swinging said plat-en to upper-case position, having aforwardly-extending arm and a depending arm, and an integralbracket-member connecting the ends of said arms, an upright row ofV-shaped teeth in the rear edge of said bracket-member, acounterbalancing spring for said machine,having its rear end forunreleasably' fastening the forward end of said spring to said machine,and instrumentalities for fastening the rear end of said spring to saidbracket-member, whereby the spring cannot be removed from said memberbut may have its pull on said bell-crank adjusted, saidinstrumentalities including a built-up link having twoside members, afiintegral rear connection for said members, a

lib

12-h terminating in an integral closed ring, means 7 its connection forthe front ends of said side members, 1ncludmg a screw passing throughone of said side members and through said closed ring to be threadedthroughthe other of said side members and upset to prevent its removalfrom said link, a collar around said screw, between said side members,having substantially the same diameter as said closed ring, and anintegral tongue on said rear connection extending forwardly between saidside members and inclining clownwardly for securely engaging in saidnotches.

i. In a typewriting machine, the combination with a bracket-memberhaving a notch therein, of a coiled wire spring having an endterminating in a closed ring or loop which engages around said bracketto be seated in said notch, and a plate having a notch therein disposedagainst said bracket so that its notch registers with and is op-.

positely disposed with respect to the notch in said bracket, wiereby toform a built-up eye whose rim engages around the wire rim of said ring,and instrumentalitiesfor undetachably fastening said plate to saidbracket in a manner that disabling of said built-up eye will beprevented.

5. In a typewriting machine, a counterbalancing coiled wire spring withan end terminatin in an inte ral closed rin or loop, a notchedbracket-member around which said ring'hooks for engaging in the notchthereof, and instrumentalitfes for building up. an eye or hole in saidbracket whose rim engages around the wire rim of said loop.

6. In a platen-shift typewriting machine of the class described havingmechanism including a bell-crank for rais'ng said platen to upper-caseposition, in combination, a depending stationary bracket-arm fixed onthe frame of said machine disposed in front of said bell-crank andarranged with a forwardly-opening notch adjacent its bottom end, atensile spring having both ends formed with an integral closed ring orloop, a built-up link for fastening one end of said spring to saidbell-crank, including two side members connected at one end by a screw,the latter passing through a closed ring of said spring, andinstrumentalities for building up an eye at the notch in said dependingarm for engaging around the other ring of said spring, including a platehaving a rearwardly-opening notch, and devices for fastening said plateon said downwardlydepending arm.

7. In a platen-shift typewriting machine of the class described havingmechanism for raising said platen, the combination with acounterbalancing spring effective for exerting a raising force on saidmechanism, and a stationarybracket on said machine having aforwardly-opening notch in which said spring may be hooked, of means forfastening said spring to said mechanism and to said fixed bracket so asto be secure against easy removal by operatives, said means including aclosed ring integrally formed in both end portions of said spring, abuilt-up link effective for unreleasably fastening one of the rings ofsaid spring to said mechanism, and instrumentalities for building up aneye for said notched member effective for unreleasably engaging theother in its forward edge for receiving a closed ring end-member of thecounterbalancing spring, of instrumentalities for building up an eye forsaid bracket effective for engaging said ring-member, so that the lattercannot be easily removed from engagement with said bracket, saidinstrumentalities including a T-shaped plate mounted on a side of saidbracket and having an upper lateral member with holes therethroughadjacent each end thereof and spaced for disposition at each edge ofsaid bracket closely thereagainst when said plate is mounted on saidbracket, said T-shaped plate having an upright member with arearward-ly-opening notch arranged to register with the notch in saidbracket to form a hole or eye in said bracket whose rim encloses thewire rim of said ring end-member, a mounting-plate disposed on theopposite side of said bracket from said T-shaped plate and havingthreaded holes disposed opposite the holes in said T-shaped plate, and ascrew arranged for passing through each hole in said T-shaped plateto bethreaded into the opposite hole in said mounting-plate and to passthrough the latter and be upset to prevent its removal.

ALFRED G. F. KUROWSKI.

